Highly sensitive and stable optical temperature sensing properties of Er3+/Yb3+ doped Lu2O2S phosphors

The Lu 2 O 2 S exhibits exceptional properties in terms of its high density, chemical stability, and optical inertia as a luminescent matrix material , however, the preparation process poses significant challenges. Herein, solid phase synthesis was improved to prepare Lu 2 O 2 S: Er 3+ /Yb 3+ phosphors with high crystallinity and homogenous particle size without agglomeration. The phosphor continuously emits bright green light under the excitation of a near-infrared 980 nm laser, which is not affected by the laser power, doping concentration and temperature. The optical thermal sensing performance of the phosphor using LIR (Luminescence intensity ratio) method was carried out, the Sr (relative sensitivity of temperature) is rather high with reaching a maximal value of 0.99 % K −1 at 363 K, indicating Lu 2 O 2 S:Er 3+ /Yb 3+ up-conversion phosphor has good temperature sensing behavior. Furthermore, through spectral overlap and luminescence decay lifetime, the energy transfer mechanism was inferred to be a quadrupole-quadrupole interaction. This work suggests that Lu 2 O 2 S:Er 3+ /Yb 3+ phosphor could be a candidate for non-contact nanothermometers, anti-counterfeit and biological imaging.